Apparatus for discharging fluent substances into well bores



March 18, 1969 APPARATUS FOR DISCHARGING FLUENT sUBsTANCEs INTO wELlJ BORES Filed Nov. 6. 1967 J. B. SHORE 3,433,302

Afro/Q fk APPARATUS FOR DISCHAHGING FLUENT SUBSTANCES INTO WELL BORES Filed NOV. 6, 1967 SheekI of 5 March 18, 1969 J. B. SHORE 3,433,302

APPARATUS FOR DISCHARGING FLUENT SUBSTANCES INTO WELL BORES linie ABSTRACT F THE DISCLOSURE The particular embodiment described herein as illustrative of the invention is directed to a well-completion tool having a reservoir adapted to contain a fluent substance to be discharged into a well bore. An extendible flow diverter is mounted around the tool and normally secured in a retracted position by a selectively-operable latch. Upon reaching a desired position in a well bore containing fluids, the latch is actuated to release the diverter for movement by first biasing means to its eX- tended position. Thereafter, continued movement of the tool along the well bore will induct well bore fluids into the reservoir ahead of the diverter to displace fluent substances from the reservoir and into the well bore behind the diverter. When the fluent substances are exhausted, the `first biasing means are selectively disabled and second biasingy means will return the diverter to its retracted position. When the tool also includes a well perforator, selectively-operable switching means may also be -provided for arming the perforator upon extension of the diverter.

Accordingly, as will subsequently become more apparent, the present invention pertains to well bore apparatus. More particularly, the present invention relates to new and improved apparatus for perforating a well bore and injecting selected fluent substances into the resulting perforations in the absence of undesirable well bore fluids.

It is widely recognized that the entrance of well control fluids or so-called mud into newly-formed perforations into an earth formation may, in time, plug the perforations so tightly that subsequent production of oil and/or gas from the formation will at least be impaired if not halted altogether. To counter this damage, suitable oilsoluble liquids and the like are commonly injected into the Well bore at least in the vicinity of Where perfora tions are to be made and a perforator is then actuated while these protective liquids are hopefully still in place. In this manner, it is believed that the soluble .protective liquids will immediately rush into the perforations as they are made and block the subsequent entry of the well Control fluids. Then, when connate fluids are produced through perforations protected in this manner, the produced fluids can easily flow into the well bore and wash away the soluble protective liquids.

Various tools have been proposed heretofore for injecting such protective liquids around a perforator just before it is actuated to produce perforations at a desired location in a well bore. For one reason or another, however, these proposed devices have not been commercially accepted by the industry. For example, one tool proposed heretofore employs a self-contained pump that will supposedly pump a limited supply of protective liquids into the annulus around the perforator and completely displace the well control fluids in this space up above an inilated packer on the tool. A similar proposed tool is arranged to employ a source of high-pressure lgas for discharging protective liquids around the perforator to disteil place the well control fluids upwardly away from the perforator.

It will be appreciated, however, that the latter one of these tools to accomplish its intended function, the protective liquids must displace a significant volume of the well control fluids against the extreme hydrostatic pressure typically encountered in well bores. Moreover, with either of these techniques, there is no assurance that the protective liquids will not be discharged at such a rate that they will merely diffuse into the surrounding well control fluids rather than envelopin-g the perforator in a substantially homogeneous mass of the protective agent that will remain in position until the perforator is actuated. Similar problems are also encountered where it is desired to perforate a formation interval and then inject a treating agent, such as acid or the like, to clean the perforations.

Accordingly, it is an object of the present invention to provide new and improved apparatus including a well perforator for reliably discharging a homogeneous mass of selected fluent substances into the well bore around the perforator before it is actuated so that once the perforator is actuated, the selected substances will enter the resulting perforations rather than being diluted by or being dispersed through other fluids in the well bore.

This and other objects of the present invention are accomplished by providing a tool including a reservoir with a selectively-extendible flow diverter which, upon extension, will force well bore fluids into the reservoir as the tool is moved through a well bore. A piston in the reservoir is responsive to the entering well bore fluids for discharging fluent substances from the reservoir to replace the withdrawn well bore fluids. Then, once the fluent substances are discharged, the flow diverter is retracted to facilitate the retrieval of the tool. In the preferred application of the tool, a well perforator is connected to the tool so that the perforator will be enveloped with the discharged fluent substances when it is actuated to perforate an earth formation.

The novel features of the present invention are set forth with particularity in the appended claims. The operation, together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings, in which:

FIGURES 1A and 1B are cross-sectional views of a portion of a preferred embodiment of a completion tool arranged in accordance with the present invention;

FIGURE 2 is a cross-sectional view taken along the lines 2 2 in FIGURE 1B;

FIGURES 3A and 3B are views similar to FIGURES 1A and 1B but showing various elements thereof in their final position; and

FIGURES 4-6 schematically depict the successive steps of how the tool shown in FIGURES 1A and 1B is used in conducting a typical well-completion operation.

Turning now to FIGURES 1A and 1B, the central portion of tool it) arranged in accordance with the present invention is shown. As seen there, the tool 10` is cornprised of an elongated housing l1 having an adapter head l2 connected at its upper end and adapted for coupling the housing to other tools (not shown) thereabove such as a typical centralizer and a casing-collar locator. Similarly, the lower end of the housing 11 is suitably adapted for connection to another tool centralizer and a perforator (not shown in FIGURE 1B). This perforator may, of course, be any one of the various types of perforators customarily employed in well-perforating operations. Although it is customary to fabricate well tools in a number of separable sections for ease of manufacture and assembly, various portions of the tool 1t) are shown in the drawings as being integral with other portions so that minor constructional details of the tool will not aiect an understanding of the invention.

In addition to the perforator (not shown in FIGURE 1B), the tool 1t) includes a reservoir 13 adapted to carry a supply of a selected fluent substance, a selectivelyoperable ilow diverter 14 adapted to displace the tluent substance from the reservoir once the diverter is enabled and as the tool is moved through a well bore, and a Control section 15 for selectively enabling the diverter and perforator upon command from the surface. The interrelation of these various elements 13-15 and the perforator will subsequently bec-ome ymore apparent.

The reservoir 13 in the upper portion of the housing 11 is formed by an enlarged longitudinal bore 16 of uniform diameter extending an appropriate distance between the upper adapter head 12 and the upwardly facing shoulder 17 formed by the junction of the enlarged bore and a smaller coincidental bore 18 extending downwardly from thereon through the housing to a termination somewhat above the lower end of the housing. A tubular conduit 19 is dependently secured and iluidly sealed to the adapter head 12 and extended downwardly along the central axis of the reservoir 13 to a position at least adjacent to the shoulder 17 for enclosing an electrical conductor 20. The electrical conductor 20 is passed through a typical fluid seal 21 in the adapter head 12 and extended on upwardly through the tool 10 for connection to conductors enclosed in a suspension cable (not shown in FIGURE 1A).

An annular piston member 22 is slidably disposed in the enlarged bore 16 and iluidly sealed therein by an external sealing member 23 engaging the housing 11 and an internal sealing member 24 engaging the conduit 19 to define upper and lower enclosed spaces 25 and 26 in the reservoir 13. In its initial position shown in FIG- URE lA, the piston member 22 is located as near as possible to the adapter head 12 to enable the lower enclosed space 26 of the reservoir 13 to receive a maximum quantity of a iiuent substance (not shown). One or more lateral ports 27 (FIGURE 1A) are provided in the upper portion of the housing 11 to admit well control fluids into the upper enclosed space 25 of the reservoir 13 as the tool 16 is used. Similarly, one or more normally-closed ports 28 (FIGURE 1B) are provided in the lower portion of the housing 12 and adapted, when open, for discharging a iluent substance from the lower enclosed space 26 of the reservoir 13. Accordingly, as will subsequently be explained, once the lower ports 28 are opened and the tool 1) is operated so as to admit a flow of well control fluids into the upper ports 27, the piston 22 will move downwardly in the reservoir 13 and displace a corresponding volume of the fluent substance from the lower space 26 through the lower ports as the well control fluids enter the upper ports and fill the upper space 25.

To facilitate the movement of the tool 10 through a Huid-filled well bore to a starting position, the diverter 14 is initially retracted to provide suticient clearance therearound between the housing 11 and the internal wall of the well casing (not shown in FIGURES lA and 1B). Similarly, although the piston 22 will normally tend to remain in its elevated position shown in FIGURE lA so long as the `diverter 14 is retracted, it is preferred to keep the ports 2S closed so that the iluent substance will not be lost from the lower space 26. It will be appreciated, therefore, that means rnust be provided to selectively extend the diverter 14 as well as to open the ports 28 upon command from the surface.

Accordingly, as shown in FIGURE 1B, the diverter 14 is preferably comprised of a exible sleeve 29 of an elastomeric material that is secured at its upper end around the central portion of the housing 11. The outer diameter of the housing 11 is reduced just below the upper end of the elastomeric sleeve 29 and appropriately formed to provide longitudinally spaced external surfaces 30 and 31 of equal diameter that are separated from one another by an external surface 32 of a more-reduced diameter. An elongated sleeve member 33 having an enlarged-diameter upper portion 34 is slidably mounted around the reduced central portion of the housing 11 and uidly sealed thereto by sealing members 35 and 36 respectively encircling the spaced external surfaces 30 and 31. The elastomeric sleeve 29 is disposed around a plurality of longitudinallyextending, outwardly-bowed flexible strips 37 that are circumferentially spaced around the housing 11 and have their upper and lower ends secured between opposed shoulders 38 and 39 on the housing and enlarged portion 34 of the slidable sleeve member 33 respectively. The lower end of the elastomeric sleeve 29 is carried below the lower end of the bowed spring strips 37 and secured around the enlarged sleeve portion 34. To insure that the spring strips 37 will remain in the outwardly bowed position shown in FIGURE lB, the enlarged portion 34 of the slidable sleeve member 33 is extended upwardly to about the middle of the spring strips and progressively enlarged so as to engage the rear surface of each strip and keep the central portion of the strips bowed outwardly.

It will be appreciated, therefore, that so long as the slidable sleeve member 33 remains in the position illustrated in FIGURE lB, the elastomeric sleeve 29 will retain its generally relaxed position. By moving the slidable sleeve 33 upwardly in relation to the housing 11, however, the sleeve shoulder 39 is moved toward the housing shoulder 33 to shorten the distance between the opposite ends of the spring strips 37 and cause their central portions to bow radially outwardly. Thus, as the slidable sleeve member 33 is moved upwardly, the outward movement of the mid-portions of the spring strips 37 will radially expand the central portion of the elastomerio sleeve 29 a corresponding distance. Conversely, by returning the sleeve member 33 downwardly, the spring strips 37 will relax and restore the elastomeric sleeve 29 to its original position.

Accordingly, it will be recognized that by releasably securing the slidable sleeve 33 in the position shown in FIGURE lB, the diverter sleeve 29 will be maintained in its fully retracted position and the tool 10 can be readily moved in a well bore with the well fluids therein freely bypassing the tool through the annular clearance around the diverter 14. To releasably secure the sleeve 33, the control section 15 includes latch means such as are provided by one or more ball members 40 that are loosely confined in lateral openings 41 spaced around the lower portion of the slidable sleeve and adapted to be partially retained in a peripheral groove 42 around the housing 11 by -a second sleeve member I43 that is telescoped over the slidable sleeve and releasably coupled to the housing 11.

An inwardly projecting lug 44 on the retaining sleeve 43 is normally engaged with a dog 45 disposed in a housing recess 46 below the retaining sleeve and pivotally mounted therein on a shaft 47 journalled to the housing 11. To retain the pivoted dog in engagement with the lug 44, the control section 15 further includes a selectively operable release such as an electrically-responsive detonator or so-called explosive squib 48 that is adapted for abutting engagement with the dog to prevent it from rotating into a non-abutting position. Biasing means, such as a compression spring 49 arranged between opposed shoulders on the sleeves 33 and 43, are provided to urge the retaining sleeve upwardly in relation to the slidable sleeve Imember once the explosive squib 48 has freed the dog 45 for rotation.

Accordingly, once the retaining sleeve 43 is allowed to move upwardly in relation to the slidable sleeve 33, a diametrical enlargement within the retaining sleeve, such as provided by longitudinal grooves or slots 50 that are respectively longitudinally aligned with the balls 40, is moved into juxtaposition with the retaining balls. It will be appreciated, therefore that by appropriately sizing the retaining balls 40 in relation to the annular clearance between the inner surface of the peripheral groove 42 and the inner surface of the sleeve 43 on the one hand and the inner surface of the slots 50 on the other h-and, the balls cannot be freed from the peripheral groove until the retainer sleeve has moved upwardly to bring the slots into registration with the balls.

By extending the retainer sleeve 43 upwardly and fluidly sealing it around the slidable sleeve 33 by sealing members 51 and 52 spaced above and below one or more ports 53 in the slidable sleeve and approximately in registration with the lower housing ports 28, the retainer sleeve also serves as a valve that selectively blocks the flow of a fluent substance from the lower space 26 until the squib 48 is detonated and the diverter 14 is extended. Once, however, the squib 48 is detonated and the retainer sleeve 43 is moved upwardly relative to the slidable sleeve 33 by the spring 49, lateral ports 54 in the retainer sleeve are brought into registration with the housing ports 28 and ports 53 in the slidable sleeve to allow the fluent substance to be exhusted therethrough as the piston 22 moves downwardly.

From the description of the tool to this point, it will be seen that once all of the various elements described so far are in their respective positions depicted in FIGURES 1A and 1B, the diverter 14 will be retained in its illustrated retracted position so long as the explosive squib 48 is not detonated. When the squib 48 in the control section is detonated, the spring 49 will urge the retainer sleeve 43 upwardly in relation to the slidable sleeve 33 which, at this time, is still secured to the housing 11 by the retainer balls 40. Once, however, the retainer sleeve 43 moves a sufficient distance upwardly to bring the slots 50 into registration with the outer surfaces of the balls 40, the combined force of a compression spring 55 carried between opposed shoulders on the slidable sleeve 33 and the housing 11 and another compression spring 56 will cause the balls to be cammed out of the circumferential groove 42 and into the enlarged annular space between the outer surface of the housing 11 and the inner surfaces of the slots 50. The spring 56 is engaged between a fixed shoulder 57 on the sliding sleeve 33 and an abutment 58 releasably secured at this time to the housing 11. The function of this movable abutment 58 and the manner of securing it will be subsequently explained.

Accordingly, it will be appreciated that once the balls 4t) are released from the circumferential groove 42, the sliding sleeve 33 will be shifted upwardly by the combined force of the springs 55 and 56 to begin bowing the spring strips 37 outwardly. The retainer sleeve 43 is, of course, carried further upwardly by the sliding sleeve 33. It will be recognized, therefore, that the spring 49 will move the retainer sleeve 43 upwardly in relation to the sliding sleeve 33 to a position where the ports 53 and 54 are in registration with one another. Thus, once the sliding sleeve 33 reaches its elevated position, the sleeve ports 53 and 54 will be in registration with the housing ports 28. At this point, the bowed spring strips 37 will have been expanded outwardly a sufficient distance to bring the elastomeric sleeve 29 either very near to or into engagement with the inner wall of the casing. This will, therefore, block the annular space between the tool 10 and the casing.

Once the diverter 14 is fully expanded and the ports 28 opened, it will be appreciated that upward movement of the tool 10 will force the well bore fluids through the ports 27 at the upper end of the housing 11 and into the upper enclosed space therein. Thus, continued upward movement of the tool 10 will be effective to move the piston 22 downwardly in relation to the housing 11. As the piston 22 moves downwardly, the fluent substance in the lower enclosed space 26 will, of course, be forced therefrom by way of the lower ports 28 and into the annulus 6 between the tool 10 and well casing below the expanded diverter 14.

When the piston 22 nears the lower limit of its travel, a depending tubular probe 59 thereon will engage the inwardly projecting ends of a plurality of inclined dogs 60 that are each carried in a housing recess 61 on a pivot pin 62 journalled to the housing 11 and have their outwardly extending upper ends abutted against the lower face of the abutment 58. Biasing means, such as reversely bent springs 63, are provided to normally maintain the upper ends of the dogs 60 extended in the position shown in FIGURE 1B to support the abutment 58 against the force of the spring 56.

As seen in FlGURES 3A and 3B, once the lower end of the depending probe 59 from the piston 22 engages and passes the inwardly projecting lower ends of the pivoted dogs 60, the dogs will be cammed to a generally erect position once the piston has reached the shoulder 17. Once the dogs `60 are pivoted into an upright position, the compressive force of the spring 56 will shift the sliding abutment 58 downwardly in relation to the sleeve member 33 until an inwardly projecting shoulder 464 thereon halts further travel ofthe abutment. With the spring 5 6 confined between the shoulders 57 and 64 on the sleeve member 33, the spring 56 will, of course, no longer be effective to urge the sleeve member upwardly in relation to the housing 11 and only the force of the spring 55 will be maintaining the sleeve member in its elevated position. Although the elastomeric sleeve 29 is shown still extended in- FIGURES 3A and 3B for purposes of illustrating that position, it will be recognized, of course, that once the abutment 58 is released, the spring strips 37 will begin expanding.

Accordingly, by selecting the spring 55 to have an effective spring force somewhat less than that required to bow the spring strips 37 outwardly against pressure forces acting downwardly on the diverter 14, once the spring 56 is immobilized between the shoulders 57 and 64, the forces tending to straighten the bowed spring strips will be effective to return the sleeve member back to its initial position. It will be realized, however, that although the spring 55 must be appropriately selected to have a spring force which, when combined with that of the spring 56, will be sufficient to bow the spring strips 37 outwardly inthe previously described manner, the spring 55 by itself will not be sufficiently strong to prevent relaxation of the spring strips once the spring 56 is immobilized. Thus, it will be appreciated that the function of the releasably secured abutment 58 is to selectively enable and disable the spring 55 by initially maintaining the spring 56 in a first position aiding the spring 55 and then, once the abutment is released, allowing the spring 56 to move to a second position in which the spring 55 is no longer effective to maintain the elastomeric sleeve 29 in its extended position.

Return of the slidable sleeve 33 will, of course, carry the outer sleeve 43 back downwardly with little or no change in its position in relation to the slidable sleeve. It will also be noted from FIGURES 3A-3B that by providing ports -65 in the upper end of the tubular probe 59, once the probe enters the bore 18 the remaining fluent substance in the lower enclosed space 26 of the reservoir 13 will continue flowing therefrom to allow the piston 22 to move to a final position abutting the shoulder 17.

Those skilled in the art will, of course, recognize that several arrangements can be employed in the control section 15 to selectively detonate the explosive squib 48 from the surface without risking a premature actuation of the perforator (not shown) therebelow. In the exemplary tool 10 it is preferred, however, to employ selectively actuated switching means to further and more positively prevent actuation of the perforator before it is in position to correctly perforate the well bore.

Accordingly, as seen in FIGURES 1B and 2, a so-called single-pole double-throw switch 66 is mounted in the housing recess 46 and adapted for movement between a first switching position electrically connecting the explosive squib 48 to the conductor 20 and a second switching position electrically connecting the conductor 20 to the perforating devices (not shown) in the perforator. To accomplish this, the switch 66 is provided with an actuator `67 that is normally engaged with cam means, such as a fiat 68, formed on a shaft 69' that is journalled at its opposite ends to the housing 11. A crank arm 70 secured to the shaft 69 and extending laterally therefrom is provided with a bifurcated end portion or clevis 71 that is movably coupled, as by a pin 72, to one end of an extension 73 dependingly secured from the lower end of the sleeve 33.

In this manner, so long as the slidable sleeve member 33 remains in the position shown in FIGURES lA-lB, only the explosive squib 48 will be electrically connected to the conductor 20. Then, as seen in FIGURES 3A3B, once the sleeve 33 is released, the switch 66 will be operated to electrically connect the conductor 20 to the perforator (not shown).

To employ the tool in a typical well-completion operation, a suitable non-plugging liquid or some selected fluent treating substance of a similar or different nature is introduced into the lower enclosed space 26 of the reservoir 13 as by a filling port that is then closed by a plug 74 (FIGURE 1A). Typical treating agents that -may be used are acid, cleaning agents, or a suitable protective or temporary plugging agent such as gelled kerosene, gelled carbon tetrachloride, or such commercially available protective formulations as Black Magic sold by Oil Base, Inc. of Houston, Tex., or Plug Ban as sold by Humble Oil and Refining Co. of Houston, Tex. Any suitable agent can be used, of course, so long as it does not react adversely with formation materials and fluids and can be removed from a perforation when it is produced. It should also be noted that improved results will be obtained where the treating substance has a lower density than that of the well control uids so that once it is injected into the well bore, the fluent substance will not tend to settle downwardly away from the diverter 14.

Once the reservoir 13 is filled and the other elements of the tool 10 are in their respective positions shownin FIGURES lA-lB, the tool is suspended from a suitable suspension cable 75 and, as seen in FIGURE 4, lowered into a well bore 76 to a position somewhat below the formation interval 77 that is to be completed. As is customary, the well bore 76 has a string of casing 78 secured therein by cement 79, with the casing extending through the earth formation 77 from which oil or gas is to be produced. A conventional well control uid or so-called mud 80 is disposed in the casing 78 in the usual manner. The suspension cable 75 includes one or more electrical conductors (not shown) and is spooled in the usual manner on a winch (not shown) at the surface.

A typical well perforator 81 is supported below the housing 51 and includes one or more perforating devices, such as shaped charges 82, adapted for selective actuation from the surface. It is preferred to also include means, such as a typical casing-collar locator 83 mounted on the tool 10, for providing indications at the surface from which the position of the completion tool in relation to the formation 77 can be established with reasonable accuracy. A casing-collar locator such as that shown in Patent No. 3,114,876 will, of course, be capable of accomplishing this.

Accordingly, as shown in FIGURE 4, with the aid of the collar locator 83, the completion tool 10 is brought to a position below the formation 77. Once the tool 10 is in position, electrical current is Iapplied from a power source at the surface to the conductor to detonate the eX- plosive squib 48 and the tool 10 is raised toward the formation interval 77 to be perforated.

When the squib 48 is detonated, the retaining sleeve 43 is moved upwardly by the spring 49 to free the balls 40 from the circumferential groove 42 and release the slidable sleeve member 33. Once the sleeve 33 is released, the combined spring force of the springs 55 and 56 will move the slidable sleeve member upwardly to extend the diverter 14 against the downwardly acting pressure forces thereon. The outer sleeve 43 will have moved upwardly relative to the slidable sleeve 33 to bring the ports 53 and 54 into registration so that, once the slidable sleeve member has moved upwardly a distance sufficient to eX- tend the diverter, the ports 53 and 54 will be in alignment with the housing ports 28.

Once the tool 10` has been enabled, the suspension cable is moved to raise the completion tool in the direction indicated by the arrow 84 in FIGURE 5. It will be recognized that since the diverter 14 blocks most, if not all, of the annular clearance space between the tool 10 and the casing 78, upward movement of the tool will be effective to displace a volume of the control fluids that is directly related to the distance the completion tool is moved. Accordingly, as the completion tool 10 is moved upwardly, the control fluids 80 entering the upper reservoir space 25 by way of the ports 27 are effective in moving the piston 22 downwardly in relation to the reservoir 13. It will be appreciated, therefore, that as the piston 22 is moved downwardly, the treating agent 85 will be eX- hausted from the lower reservoir space 26 through the lower ports 28 and into the annulus between the tool 10 and the casing 78. The volume of treating agent 85 exhausted, as at 86, will, of course, be equal to the volume of the control fluids 80 entering the upper reservoir space 25. Thus, the volume of treating agent 85 discharged will be directly related to the distance the tool 10 is moved and the treating agent will be expelled at a rate corresponding to the speed at which the tool is moved.

Of particular significance, it will be noted that since the treating agent 8S is discharged into the annulus below the expanded diverter 14 as the well control fluids '80 formerly occupying that same clearance space are entering the upper reservoir space 25, the discharged treating agent 86 will till this annular clearance space rather than being diffused into the control fluids as has been the case heretofore. This will, of course, result in a more complete envelopment of a homogeneous mass in that interval of the well bore 76 that is to be perforated. Moreover, the diverter 14 will prevent the well control fluids 80 above the diverter from settling into the discharged treating agent 86. Since the treating agent has been selected to have a lower density than that of the well control fluids 80, there will Ibe little or no tendency for the well control fluids 80 `below the diverter 14 to dilute the discharged mass of treating agent 86. Thus, the present invention insures that the fluent mass 86 will completely fill the annulus below the diverter 14 in a more consistent manner than has been possible heretofore.

As seen in FIGURE 6, as the tool 10 is moved further upwardly, the perforator 81 is brought into the homogeneous mass of discharged treating agent 86 opposite the formation 77. Then, once it is determined that the perforator 81 is correctly positioned, electrical current is applied from a power source at the surface through the suspension cable 75 to actuate the perforator and produce a corresponding number of perforations 87 through the casing 78 `and the cement sheath 79 into the earth formation 77. It will be recalled that the release of the retaining sleeve 43 will have actuated the switch 66 to connect the perforator 81 to the conductor 20. Although the tool 10 can be halted before the perforator 81 is actuated, it is preferred to continue moving the tool 10` upwardly as the perforator is actuated to insure that the last portion of the treating agent is expelled from the reservoir 13 a short time after the Well bore is perforated. It will be appreciated, of course, that the position of the perforator 81 in relation to the formation interval 77 being completed will be known at all times by virtue of typical depth indicators at the surface whose accuracy is confirmed by depth-correlation devices on the tool such as the casing-collar locator 83.

The effective volume of the reservoir 13 must, of course, be determined to insure that when the perforator 81 is actuated, it is completely surrounded by a homogeneous mass, as at 86, of the treating agent `85. Moreover, where an enclosed retrievable carrier type perforator 81 is employed, the effective volume of the reservoir 13 should be sufficient to accommodate the volume of the treating agent 86 that will fill the carrier once it is perforated. In a typical arrangement of the tool 10 where an enclosed retrievable carrier perforator is used, as at 81, the effective length of the lower enclosed space 26 will accordingly be in the order of about 1.5 to 2.0 times the length of the carrier. With relative proportions of this order, -a continuing discharge, as at 86, of the treating agent 85 will be obtained as the tool 10 is moved further upwardly after the perforator 81 is actuated to insure that only the discharged treating agent 86 can enter the perforations 87 once they are produced.

By the time the piston 22 has reached the lower limit of its travel as determined by the shoulder 17, the tubular probe 59 thereon will have -actuated the pivoted latch fingers 60 to release the movable abutment 58 and disable the spring 55. Once the spring 55 is disabled, therefore, the elastomeric sleeve 29 will be restored to its retracted position and the Well bore fiuids 80 can again freely bypass the tool 1()` as the tool is returned to the surface.

Accordingly, it will be appreciated that the present invention has provided a new and improved tool by which a well bore can be perforated to allow only selected uent substances to enter the perforations. By using this tool in the imanner described above, the apparatus of the present invention will enable a homogeneous mass of a selected substance to envelop a perforator before it is actuated so that only the substance will contact the formations when they are perforated.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, therefore, the aim in the Iappended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A well-completion tool adapted for passage along a well bore containing uids, and comprising: means adapted for withdrawing well bore fluids from an interval of a well bore in response to movement of said tool along such an interval and replacing such withdrawn fluids with a fluent substance including a reservoir on said tool and adapted to contain a fluent substance, first passage means between a leading portion of said tool and a first portion of said reservoir and adapted to induct well bore fluids into said reservoir as said tool is moved along a well bore interval, second passage means between a second portion of said reservgir and a trailing portion of said tool and adapted to discharge fluent substances from Said reservoir into a well bore interval as said tool is moved therealong, and selectively-operable fiowdiverting means around an intermediate portion of said tool and adapted for movement between a first position for allowing relative fiow of well bore fluids around said tool and a second position for restricting relative fiow of well bore fluids around said tool as said tool is moved along a well bore interval; first means adapted for moving said How-diverting means from said first position to said second position in response to a command from the surface; and second means, operable after said fiowdiverting means are in their said second position, for returning said fiow-diverting means to said first position.

2. The well-completion tool of claim 1 further including: piston means slidably disposed in said reservoir for isolating said reservoir portions from one another.

3. The well-completion tool of claim 1 wherein: said first means include first and second spring means between said tool and said fiow-diverting means for urging said flow-diverting means toward said second position, and latching means releasably securing said dow-diverting means in said first position and operable in response to such a command for freeing said How-diverting means for movement by said first and second spring means to said second position; and said second means include means responsive to discharge of fluent substances from said reservoir for disabling at least one of said first and second spring means, and third spring means operative upon disabling of said one spring means for returning said now-diverting means to said first position.

4. The well-completion tool of claim 1 further including: piston means slidably disposed in said reservoir for isolating said reservoir portions from one another and adapted for travel therein from said first reservoir portion into said second reservoir portion; and wherein said first means include first and second spring means between said tool and said flow-diverting means for urging said fiow-diverting means toward said second position, and means releasably latching said fiowdiverting means in said first position and operable in response to such a command for freeing said fiow-diverting means for movement by said first and second spring means to said second position; and said second means include means responsive to travel of said piston means into said second reservoir portion for disabling at least one of said first and second spring means, and third spring means operative upon disabling of said one spring means for returning said How-diverting means to said first position.

5. The well-completion tool of claim 1 further including: selectively-operable perforating means on said trailing portion of said tool and adapted for perforating an earth formation traversed by such a well bore interval; and means normally disabling said perforating means and operable upon movement of said flow-diverting means toward said second position for enabling said perforating means.

6. The well-completion tool of claim 1 further including: means normally closing at least one of said passage means and operable upon movement of said fiowdiverting means toward said second position for opening communication through said one passage means.

7. The Well-completion tool of claim 1 further including: selectively-operable perforating means on said trailing portion of said tool and adapted for perforating an earth formation traversed by such a well bore interval.

8. A well-completion tool adapted for passage along a well bore containing fiuids, and comprising: a body having an internal chamber adapted to contain a fluent substance; first and second passages respectively providing fluid communication between first and second portions of said chamber and first and second spaced exterior locations on said body; and selectively-operable means responsive to movement of said tool along an interval of a well bore for diverting well bore fluids from that interval into said first passage to displace a fluent substance contained in said chamber from said second passage and into that interval including a fiexible sleeve mounted around said body between said spaced exterior locations and adapted for -movement between a retracted position and an extended position, means releasably latching said flexible sleeve in its said retracted position and adapted for selective actuation to release said fiexible sleeve for movement from its said retracted position to its said extended position, first means operable upon actuation of said latching means for moving said flexible sleeve to its said extended position, and second means operable upon displacement of a fiuent substance from said chamber for returning said flexible sleeve to its said retracted position.

9. The well-completion tool of claim 8 wherein said second means include: a piston sealingly disposed in said chamber and movable in response to induction of well bore fluids into said rst chamber portion on one side of said piston to displace a iiuent substance confined in said second chamber portion on the other side of said piston through said second passage and into that well bore interval.

10. The well-completion tool of claim 9 further including: a well perforator connected to said body adjacent to said second exterior location thereon and adapted for selective actuation for perforating an earth formation adjacent such a well bore interval.

11. The well-completion tool of claim 8 wherein: said first means include iirst biasing means operative upon actuation of said releasable latching means for moving said flexible sleeve to its said extended position; and said second means include means for disabling said iirst biasing means, and second biasing means operative upon disabling of said first biasing means for returning said exible sleeve to its said retracted position.

12. The well-completion tool of claim 11 wherein said second means include: a piston sealingly disposed in said chamber and movable in response to entrance of well bore uids into said first chamber portion on one side of said piston to displace a fluent substance coniined in said second chamber portion on the other side of said piston through said second passage and into that well bore interval; and means on said piston adapted for actuating said disabling means whenever said piston has neared the end of said second chamber portion.

13. The well-completion tool of claim -12 further including: a well perforator connected to said body adjacent to said second exterior location thereon and adapted for selective actuation for perforating an earth formation adjacent such a well bore interval', and means normally deactivating said perforator and responsive to release of said flexible sleeve for movement to its said extended position for activating said perforator for operation.

14. A well-completion tool adapted for suspension in a well bore containing fluids, and comprising: a body having a iirst portion defining a reservoir adapted to receive a fluent substance and a second portion adapted to carry well-perforating means; rst and secon-d means respectively providing fluid communication between lirst and second portions of said reservoir and first and second longitudinally-spaced ports in the exterior of said body; a flow diverter including a iiexible sleeve disposed around said body between said ports and having one end secured to said body, and a member secured to the other end of said iiexible sleeve and movable in relation to said body between a first location where the central portion of said sleeve is in a retracted position along said lbody and a second location where said central sleeve portion is free to move outwardly to an extended position a-way from said body; first means normally positioning said movable member in its said iirst location and responsive to a command 'from the surface for moving Said movable member to its said second location to carry said central sleeve portion to its said extended position whereby movement of said tool along a well bore interval will be effective to induct well bore iiuids into said `first port ahead of said flow diverter and displace a, uent substance in said reservoir from said second port tothe rear of said flow diverter into a well bore and around said second body portion; and second means responsive to such movement of said tool for returning said lmovable member to its said first location to restore said central sleeve portion to its said retracted position whenever a iiuent substance has been displaced from said reservoir, and including a plurality of longitudinally extending resilient strips circumferentially and respectively having one terminal portion secured to said body and another terminal portion secured to said movable member whereby movement of said movable member from its said first location to its said second location will bow the intermediate portions of said resilient strips outwardly to move said central sleeve portion to its said extended position.

15. The well-completion tool of claim 14 further including: well-perforating means carried by said second body portion; and means normally disabling said Wellperforating means and responsive to movement of said movable member toward its said second location for enabling said well-per'forating means.

16. The well-completion tool of claim 14 further including: valve means normally blocking said second port; and means connecting said movable member and said valve means for opening said second port upon movement of said movable member toward its said second location.

17. The well-completion tool of claim 14 wherein: said resilient strips, when bowed, develop a combined spring force urging said movable member from its said second location toward its said irst location; said first means include first and second springs respectively secured between said movable member and said tool body normally urging said movable member from its said rst location toward its said second location with a total spring force greater than said combined spring force; and said second means include -means releasably securing at least one of said rst and second springs in operative relation, and means operative upon displacement of a fluent substance from said reservoir for releasing said spring-securing means to disable at least one of said rst and second springs and allow said resilient strips to return said movable member to its said first location.

v18. The well-completion tool of claim 14 wherein said first means include: first spring means between said movable member and said tool body normally urging said movable member toward its said second location, and means releasably latching said movable member in its said iirst location and releasable in response to such a command from the surface yfor freeing said movable member and allowing said rst spring means to carry said movalble member to its said second location.

19. The well-completion tool of claim 18 wherein said resilient strips between said movable member and said tool body are operable for urging said movable member from its said second location toward its said first location with a force less than the force of said first spring means; and -wherein said second means include means responsive to emptying of fluent substances in said reservoir for disabling said iirst spring means.

20. The well-completion tool of claim 18 wherein said second means include: a piston member slidably disposed in said first portion to a final position in said second porone another and movable therein from an initial position in said iirst portion to a final portion in said second portion once a fluent substance is emptied from said reservoir, and include means for disabling said first spring means once said piston member reaches its said nal position.

21. A Well-completion tool adapted for suspension from an electrical cable in a well bore containing uids, and comprising: a body having an axial bore therein adapted to contain a fluent substance and iirst and second ports spaced apart and providing iuid communication between said bore and the exterior of said body; piston means slidably disposed in said axial bore adjacent to said lirst port and adapted for movement along said axial bore toward said second port in response to entrance of well bore iiuids into said first port for displacing a fluent substance in said axial bore from said second port; uiddiverting means on said tool and adapted for diverting well bore fluids into said -iirst port as said tool is moved along a well bore with said irst port ahead of said second port and including an elastomeric sleeve disposed around said body between said spaced ports and having one end secured to said body, a member secured to the other end of said elastomeric sleeve and slidably disposed around said body for movement between a first location maintaining said elastomeric sleeve in a retracted position along said body and a second location freeing the central portion of said elastomeric sleeve for radial movement outwardly from said body to an extended position, and a plurality of longitudinally-extending spring strips circumierentially spaced around said body within said elastomeric sleeve and respectively having one of their ends secured to said body and their other end secured to said slidable member whereby movement of said slidable member to its said second location will lbow the intermediate portions of said spring strips outwardly to carry said central sleeve portion to its extended position and develop a first spring force tending to return said slidable member to its said first location; first and second springs respectively mounted between opposed shoulders on said body and said slidable member and normally urging sai-d slidable member toward its said second location with a combined second spring -force greater than said rst spring force; means releasably latching said slidable member in its said Iiirst location and releasable in response to an electrical signal from such a cable to free said slidalble member for movement to its said second location by said second spring force; and means responsive to movement of said piston member for disabling at least one of said springs Whenever said piston member has reached the end of its travel to allow said spring strips to return said slidable member t its said tirst location and retract said elastomeric slee-ve.

22. The well-completion tool of claim 21 further including: a well perforator connected to said body adjacent to said second port and including electrically-responsive shaped charge means; and switching means normally disconnecting said shaped charge means and responsive to movement of said slidable member to its said second location for electrically connecting said shaped charge means to such a cable.

23. The well-completion tool of claim 21 further including: valve means on said slidable member for blocking fluid communication through said second port so long as said slidable member is in its said first location and movable thereby to open such fluid communication as said slidable member moves to its said second location.

24. The well-completion tool of claim 21 wherein: at least one of said opposed shoulders is movable with respect to said body and said slidable member; and said disabling means include means releasably securing said movable shoulder to its associated member, and means on said piston member adapted for engagement with said releasable securing -means when said piston member has reached the end of its travel for releasing said movalble shoulder to disable at least one of said first and second springs and reduce said second spring torce to a spring force less than said first spring force.

25. The well-completion tool of claim 24 further ncluding: valve means connected to said slidable member for blocking fluid communication through said second port so long as said slidable member is in its said rst location and movable thereby to open such fluid communication as said slidable member moves to its said second location.

26. The well-completion tool of claim 25 further including: a |well perforator connected to said body adjacent t0 said second port and including electricallyresponsive shaped charge means; and switching means normally disconnecting said shaped charge means and responsive to movement of said slidable member to its said second location for electrically connecting said shaped charge means to such a cable.

27. A Well tool adapted for passage along a well bore, and comprising: a body; an actuator movably disposed on said body for movement thereon between first and second spaced locations; means adapted for contacting a wall of a well bore operatively arranged between said actuator and said body for movement between a retracted position adjacent to said body and an extended position away from said body in response to movement of said actuator between its said spaced locations; lirst spring means normally urging said actuator toward its said second location; means releasably latching said actuator in its said tirst location to said body and adapted for release in response to a command from the surface for freeing said actuator and allowing said first spring means to carry said actuator to its said second location and move said wall-contacting means to one of said positions; second spring means for urging said actuator from its said second location toward its said first location with a force less than the force of said first spring means; and selectively-operable means for disabling said first spring means to allow said second spring means to move said actuator back to its said first location and return said wall-contacting means to the other of said positions.

28. The Well tool of claim 2.7 wherein: said second spring means are enabled by movement of said actuator toward its said second location.

29. The well tool of claim 27 further including: first and second spring mounts on said body and said actuator respectively, said first spring mount being movable in relation to its associated member; and wherein said first spring means include a spring normally carried between said first and second spring mounts; and said disabling means include means releasably securing said movable spring mount to its said associated member, and selectively-operable means for releasing said securing means from said movable spring mount.

30. The well tool of claim 29 wherein: said second spring means are coupled between said wall-contacting means and said actuator for moving said wall-contacting means to said one position and enabling said second spring means as said actuator is moved toward its said second location.

References Cited UNITED STATES PATENTS 2,490,350 12/1949 Grable 166-214 X 2,781,852 2/1957 Rumlble 166-196 X 3,020,961 2/1962 Orr 166-165 3,090,441 5/1963 Smink et al. 166--162 3,138,206 6/1964 Bruce et al 166--35 X DAVID H. BROWN, Primary Examiner.

U.S. C1. X.R. 16o- 55.1, 196; 175-452 2;;230 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. SJLSMSOQ Dated March 18, 1969 Inventor(s) James B ShOIe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column l2, line 50, delete entire line, should read in said reservoir for isolating said reservoir portions from --5 Column l2, line 52, delete "portion" (second occurrence) should read position SIGYED AND SEALED Aus 4 1970 Edwa M. mekaar, nl mmm E;n www, JR.

nesting Offir Soumissions:` or `Paton 

